shared_context & copy_texture bug on windows XP

Hi all,

I'm trying to use the shared_context function to create a dynamic texture for a sphere.
I've developed a patch that works perfectly on osX, but not on XP (and I need to install the patch on a PC for a museum installation). I've test on 3 different PC with windows XP (one is a macbookPro unibody using Bootcamp). The problem occurs when I use big textures (it works for 320x240, but I need a 2048x1024 texture), and when I switch into fullscreen mode (apply a white texture whatever the size). Does anyone have an idea or a trick to make this work ?

thanks,

Jean-Michel

Here is a demo patch that illustrates this pb: